Calcining-furnace.



10.850,041. PAIENTBD APR. 9, 19107.

' T MQNEAL GALCINING fuRNAoE. APPLIOATION FILED DEU. 19, 1906.

A TTOHNEyS THOMAS MCNEAL, OF KANSAS CITY, MISSOURI.

cALolNlNe-FURNACE.

Specification of Letters Patent.

Patented April 9, 1907.

Application filed December 19,1906. Serial No. $48,524:.v

Improved Calcining-Furnace, of which theA following is a full, clear,and exact description.

This invention relates particularly to improvements in scrapers oragitators used in apparatus for calcining plaster and like material, anobject being to so construct the scraper that it will engage closelywith all parts of the convex bottom of the calcining vessel, thusthoroughly stirring the material in the vessel. Other objects of theinvention will appear in the general description.

I will describe a calcining-furnace embodying my invention and thenpoint out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the figures.

Figure 1 is an elevation, partly in section, of a calcining-furnaceembodying my invention. Fig. 2 shows the scraper in plan. Fig. 3 is aperspective view of a portion of the scraper. Fig. 4 is a detailshowing' the outlet and controlling door therefor, and Fig. 5 is asection on the 'line 5 5 of Fig. 3. 4

The general construction of the furnace i similar to that shown in thepatent` granted to me under date of February 16, 1897, No. 577,059.

Referring to the drawings, 10 designates a calcining vessel havingcross-fines 11 for the passage of products of combustion, and the vesselis provided with a convex bottom 12, the object in convexing the bottombeing to provide a comparativelylarge area of heatingsurface, and thevessel is arranged over av heating-chamber 13, the said heating-chamberand the vessel being placed in a casing 14, of brick or other suitablematerial. V

The scraper or agitator comprises a bar 15,'

which is longitudinally curved or corresponding practically to thecurvature of the arranged on the opposite side of the bar from thescrapers 18, and the several scrapers are connected to the bar by links20. At the outer ends of the bar are scrapers 21, which have portionsfor engaging upon the bottom of the calcining vessel and alsohorizontally-disposed portions for engaging against the wall of thevessel. The object of the horizontallydisposed portions of these outerscrapers is to permit their passing over the outlet 22 from thecalcining vessel and communicating with a spout 23. The outlet isprovided with a plurality of transverse bars 24, which form guides forthe horizontally-disposed portions of said end scrapers. These endscrapers are also connected to the bar by means of links 20.

The main feature of my present invention resides in the central scraper,which as a whole is practically S-shaped; but it consists of twooppositely-curved sections 26 27, pivotally connected together, asindicated at 28, and at the inner ends the sections haveoutwardly-extended portions 29, practically at right angles to the bodyportion. The outer ends of the sections 26 and 27 are connected to thebar 15 by links 30. By making this central scraper of twopivotally-connected sections and by providing the proj ections 29 thesaid central scraper will bear closely upon the convex bottom of thecalcining vessel, and, as indicated in Fig. 5, the lower edges 31 of thesections in the extensions 29 are beveled, so as to provide sharpcutting edges, which engage with said bottom of the calcining vessel.

The outlet from the vessel is normally closed by a sliding gate or valve32, from which a hand-rod 33 extends upward.

In operation the'several scrapers will engage by gravity upon theconvexbottom of the calcining vessel and obviously will follow the contour orcurve thereof.

II'aving thus described my invention, I claim as new and desire tosecure by Letters Patent* 1. The combination with a furnace, of acalcining vessel arranged therein and having a convex bottom, a shaftextended vertically in said vessel, a bar attached to the lower end ofsaid shaft, a plurality of scrapers havin link connection with the bar,and a centra scraper consisting of two sections curved in IOO rob

cining vessel arranged therein and having a convex bottom, avertically-extended shaft in the vessel, a bar carried by said shaft, aplurality of Scrapers carried by the bar, and a central scraperconsisting of two pivotallyconnected sections curved in oppositedirections, the inner or pivotal ends of said sections being extendedoutward at substantially right angles to the sections.

3. In a calcining device, a furnace, a calcining vessel arrangedtherein, a vertical shaft in the vessel, a bar carried by said shaft, aplurality of Scrapers-having swinging connection with the bar, a centralscraper consisting of two pivotally-connected sections, the inner orpivotal ends thereof having outward extensions, and link connectionsbetween the outer ends of said sections and said bar.

4. In a calcining device, a furnace, a calcining vessel arranged thereinand having a convex bottom, a shaft arranged vertically in the vessel, abar carried by the shaft and conforming to the curvature of the bottomof the vessel, a plurality of Scrapers carried by said bar, a centralscraper consisting of two pivotally-connected sections curved inopposite directions and having outward projections at their inner ends,the lower edges of said sections being inclined to form cutting edges,and link connections between the outer ends of the sections and the bar.

In testimony whereor1 I have signed my name to this speciicatio'n in thepresence of two subscribing witnesses.

THOMAS MCNEAL.

Witnesses:

N. L. JoNEs, L. SIMPSON.

